Set Default File Format on ESRI Print Widget

Question

I'm using the Print widget in the ArcGIS JavaScript API (4.4) and would like to set the File format to default to PDF instead of PNG8. I've read through the documentation and don't see a straightforward way of setting that parameter.

Does someone know of a way to do this?

I'd like to minimize the number of steps my users have to take in order to get a document they can print successfully - PDFs are the best option in my case.

Answer 1

As is often the case, after posting the question I thought of something else to try.

I have not found a way to control the default file setting on the Widget itself - but you can control it when you set up the geoprocessing service.

The format you choose when you run the tool (prior to publishing) is the format that shows up as the default in the widget:

Then the widget loads like this: